Instruction manual
Guppy PRO Technical ManualV4.1.0
138
Controlling image capture
• Line 1 shows the broadcast command, which stops all cameras connected
to the same IEEE 1394 bus. It is generated by holding the Shift key down
while clicking on Write.
• Line 2 generates a broadcast one_shot in the same way, which forces all
connected cameras to simultaneously grab one image.
Jitter at start of exposure
The following chapter discusses the latency time which exists for all Guppy PRO
CCD models when a hardware trigger is generated, until the actual image expo-
sure starts.
Owing to the well-known fact that an Interline Transfer CCD sensor has both a
light sensitive area and a separate storage area, it is common to interleave
image exposure of a new frame and output that of the previous one. It makes
continuous image flow possible, even with an external trigger. The uncertain
time delay before the start of exposure depends on the state of the sensor. A dis-
tinction is made as follows:
FVal is active the sensor is reading out, the camera is busy
In this case the camera must not change horizontal timing so that the trigger
event is synchronized with the current horizontal clock. This introduces a maxi-
mum uncertainty which is equivalent to the row time. The row time depends on
the sensor used and, therefore, can vary from model to model.
FVal is inactive the sensor is ready, the camera is idle
In this case the camera can resynchronize the horizontal clock to the new trigger
event, leaving only a very short uncertainty time of the master clock period.
Model Exposure start jitter (while FVal) Exposure start jitter (while camera idle)
Guppy PRO F-031 14.2 μs 2.9 μs
Guppy PRO F-032 24.3 μs 3.0 μs
Guppy PRO F-033 23.4 μs 2.6 μs
Guppy PRO F-046 27.4 μs 2.6 μs
Guppy PRO F-095 35 μs 6.9 μs
Guppy PRO F-125 33.2 μs 5.0 μs
Guppy PRO F-146 56.0 μs 13.7 μs
Guppy PRO F-201 29.5 μs 10.3 μs
Guppy PRO F-503 not applicable not applicable
Table 71: Jitter at exposure start (no binning, no sub-sampling)
Note
• Jitter at the beginning of an exposure has no effect on
the length of exposure, i.e. it is always constant.